Poly(arylene sulfides) (hereinafter, also referred to as “PAS”), represented by polyphenylene sulfide (hereinafter, also referred to as “PPS”), are engineering plastics having excellent heat resistance, chemical resistance, flame retardancy, mechanical strength, electrical characteristics, dimensional stability, and the like. PAS can be formed into various molded products, films, sheets, fibers, and the like by general melting processing methods such as extrusion molding, injection molding and compression molding, and therefore PAS is widely used in an extensive range of technical fields including those of electrical instruments, electronic instruments, automobile instruments and packaging materials.
Examples of methods for producing PAS include methods that use batch systems, but a method which uses a continuous system has also been proposed. For example, Patent Documents 1 to 3 disclose PAS continuous polymerization devices in which pressure resistant polymerization vessels are connected in series, and the reaction solution is transferred between the polymerization vessels by a pressure difference, and also methods for continuously polymerizing PAS using the devices thereof.